Scoot over for human being No. 7,000,000,000

Monday

Oct 31, 2011 at 12:01 AMOct 31, 2011 at 10:35 AM

SAN ANTONIO - The 7? billionth human is expected to be born today, but an expert who helps do the counting says that event comes as the Earth undergoes a demographic shift toward slower population growth.

SAN ANTONIO — The 7?billionth human is expected to be born today, but an expert who helps do the counting says that event comes as the Earth undergoes a demographic shift toward slower population growth.

According to the United Nations Population Fund, the 7 billionth child is most likely to be a boy born in India or China, but the trend of fertility in the longer term is in a different direction, says Dudley Poston, a professor of sociology and demographics at Texas A&M University,

For the first time ever, the human reproduction rate is slowing, in many places slowing significantly, and the slowing growth is not only happening in Europe and Japan, he says.

“Once your fertility rate drops below two, it is very very hard to get it to go back up again,” Poston said.

“We now have 75 countries in the world where the fertility rate is below two,” meaning the average woman is having fewer than two children.

That is far below the rate of 2.2 to 2.3 considered optimal to hold the population steady, factoring in the number of females who have no children or who don’t live to reach childbearing age.

While he says Europe and the industrialized democracies of eastern Asia are the “poster children”

“Japan is losing more people today than they’re gaining,” Poston said. “South Korea has an alarmingly low fertility rate, 1.1.”

Not long ago, the opposite was true. In 1970, the average fertility rate worldwide was 4.5, leading to predictions of demographic doom in books such as Robert Silverberg’s The World Inside and Stanford University biologist Paul Ehrlich’s The Population Bomb.

They saw a world where hoards of wildly reproducing humans desperate for dwindling food supplies would destroy social cohesion and spark wars and societal unrest.

But a funny thing happened on the way to population Armageddon. Poston says the fastest growth period in the history of the world was in the mid- to late 1960s, which prompted dystopic predictions.

“When Paul Ehrlich wrote that book, the world was growing at about 2 percent per year,” Poston said. “Now, we’re growing at about half that.”

Poston says a combination of factors led to what may be the most significant demographic shift ever. In the industrialized West, improved methods of birth control and greater opportunities for women in society meant the end of 5,000 years of women generally being considered society’s baby-makers.

In China, there has been aggressive enforcement of a “one child” policy, drastically reducing population growth rates and leading to a surplus of males.

Worldwide, urbanization has reduced the need for large families beneficial in rural agricultural areas.

Reasons for significant growth rate declines in places such as Iran, where the rate has fallen from 7.0 in 1974 to 1.9, remain more of a mystery, but Poston says they probably can be traced to cultural changes that can be very difficult to reverse.

“We have been growing very, very fast in the world, and now we’re starting to slow down.”